Brixton Academy is an iconic live music venue in South London.
I've had the opportunity to put a variety of different sound systems in over the last few years so I thought I'd write this up and share some of my findings in the hope that it's helpful for someone down the line.
First Look
Built as a large cinema in 1929, the venue features a 'hung' projection booth below the circle, rather than above. This was an unusual design but allowed the projector to be directly in front of the screen. For us, it means that the balcony is higher than usual, and that the split between the two levels is a lot larger than with many other venues.
Not immediately obvious is the curved plaster ceiling that's very acoustically reflective, and forms a strong flutter echo with the floor of the stalls. This can really hurt the intelligibility in the first few rows, especially combined with how far off axis the centre is from the main hangs. Luckily this echo dies down a lot when the audience comes in, but the room is notoriously challenging at soundcheck when it's empty.
"Simple Left-Right" Setup
The traditional PA design in this room is a simple Left-Right - generally something along the lines of 12-16 boxes of K2 a side. There's 8 rigging points in front of the proscenium, and the outer points have 2 motors hung from an O-ring on each side allowing you to fly your hang as an active bridle.
There's no space for subwoofers in front of the stage, and the barrier can't be moved, so subs have to be either side. This is not ideal and you definitely end up with more Sub in FOH, especially as it's on a riser, which is something to watch out for with any PA design.
As with all theatres, you need to work the trim height around the balcony shape, and Brixton needs a big split between the two floors. I've found that a 10 degree split in the middle of the hang does it quite well, generally with 5 boxes aimed at the balcony, leaving 7 for the stalls. If your chosen brand of PA can't do 10 degrees, you'll want to consider 'blanking' out a box to get that angle.
In terms of trim height here's a compromise to be had:
If the PA is too high the balcony will shade the rear of the stalls, but you'll get a better angle on the balcony, so you can use less extreme filtering and throw less sound into the ceiling.
If the PA is too low, you'll get better coverage in the stalls, but the top boxes will shoot up at nearly the same angle as the balcony, making it sound very harsh and empty at the back.
Split System "V1"
The first split system I flew in Brixton used a single central hang to cover the entire balcony area, leaving the normal Left-Right system to take care of the stalls. We put 6 boxes of K2 upstairs, and 9 a side downstairs.
Instantly, it was noticeable that we weren't exciting the room as much, especially the balcony edge and ceiling. It performed really well downstairs and really highlighted the potential merits of this idea.
The issue with this specific system was two-fold, firstly the HF dispersion on the upstairs K2 wasn't quite wide enough to cover right to the front corners of the the balcony - it's there, but struggles to compete with the low-mid coming off the downstairs hangs.
Secondly, there's no stereo image in the balcony, which is okay, but makes it sound a little more empty than it should up there.
Split System V2
So the natural progression was to add a second hang upstairs to fill in the coverage and provide more of a stereo image for the balcony in general. For this we used the outer lighting points above the front of the stage. These points have hoists permanently rigged, so you just need your own motor cable if they're not being run with the lighting truss.
This setup provided much better coverage in the balcony and is now my preferred config in brixton. It takes more time to rig and uses more boxes, but is worth it in my opinion.
Future
In the next month of so I'm due to take a couple of D&B KSL rigs into Brixton, so I'm interested to see how they stack up and will try to update this page afterwards.